Remove Linked List Elements — Dummy Head

# Python
def removeElements(head, val):
    dummy = ListNode(0, head)
    cur = dummy
    while cur.next:
        if cur.next.val == val: cur.next = cur.next.next
        else: cur = cur.next
    return dummy.next

// Java
public ListNode removeElements(ListNode head, int val) {
    ListNode dummy = new ListNode(0, head), cur = dummy;
    while (cur.next != null) {
        if (cur.next.val == val) cur.next = cur.next.next;
        else cur = cur.next;
    }
    return dummy.next;
}

// C++
ListNode* removeElements(ListNode* head, int val) {
    ListNode dummy(0, head), *cur = &dummy;
    while (cur->next) {
        if (cur->next->val == val) cur->next = cur->next->next;
        else cur = cur->next;
    }
    return dummy.next;
}